Search

• This paper proposes a fault location method based on composite traveling wave, which can easily eliminate the traveling wave from adjacent lines. • The traveling wave from other adjacent lines, which is never detailed discussed in previous research, hinders the accurate identification of wavefront. • The refraction coefficient of busbar with multiple transmission lines is negative for current traveling wave, but positive for reflection coefficient. • The time–frequency matrix is able to present the energy of traveling wave in wideband. As the speedy expansion of power gird, the traveling wave fault locator in substation may not always connect to newly added transmission lines in time, which reduces the effectiveness of fault locator. In this paper, an adjacent fault-free line based fault location scheme for newly additional line is proposed. Since the traveling wave from adjacent fault-free line results in severe difficulty for identification of traveling waves from faulty line, the time–frequency matrix is performed to screen traveling waves. Firstly, in order to remove the influence of waves from remote terminals of adjacent fault-free line, the current refraction coefficient is theoretically analyzed. Due to the negative refraction coefficient, traveling waves from remote terminals of adjacent fault-free line can be reduced by the proposed composite traveling wave. Secondly, the time–frequency matrices of composite traveling wave and original traveling wave is obtained by S-transform. Then, these matrices are applied to form ratio matrix which thoroughly eliminated waves from remote terminals of fault-free lines. Moreover, the robustness of the proposed fault location scheme is thoroughly validated by the simulation of PSCAD/EMTDC. Finally, the proposed fault location method has the great accuracy in simulation tests and field data test. [ABSTRACT FROM AUTHOR]

• Linearized HVDC Link model implemented, which is applicable to dynamic performance studies of power electronic equipment considering electromagnetic transients of electrical network; • Using of generalized switching functions and dynamic phasors in the proposed model; • Mitigation of poorly damped oscillation problems due converter interactions with network; • Model validation and application using PSCAD as benchmark; • Simulation of a large-scale model of Brazilian system with HVDC Multi-infeed configuration. This paper presents a linearized HVDC link model, which was implemented in PacDyn software and is applicable to dynamic performance studies of power electronic equipment considering electrical network electromagnetic transients, differently from electromechanical studies where the network dynamics is usually neglected. The proposed HVDC model was developed employing equivalent switching functions concepts and dynamic phasors. Simulations and results for small and large-scale test systems are presented. Model validation is performed through comparisons between results obtained by PacDyn and PSCAD. In sequence, there are practical examples of controller tunning considering adverse dynamic interaction mitigation between HVDC Link and electrical grid. The final results on a large-scale model of the Brazilian power system demonstrate that the proposed HVDC model can be used in actual engineering studies. [ABSTRACT FROM AUTHOR]

• Developing a comprehensive model of a transformer winding which incorporates skin effect, proximity effect, and eddy current losses in the core, • Studying the effects of the core at high frequencies using simulations and measurements, • Investigating the skin and proximity effects on the frequency response and impedance characteristics of transformers, • Performing empirical measurements to validate the reduced influence of the core at high frequencies. This paper investigates the high-frequency transformer losses attributed to eddy currents in both conductors and the core. A comprehensive model of a transformer winding is presented, meticulously incorporating skin and proximity effects. The winding resistance increase due to these effects is determined by applying analytical and finite element methods. The investigation highlights that eddy current losses in the magnetic core notably increase the resistance of each winding section in low frequencies. However, the impact of these losses diminishes as the winding length approaches the voltage wavelength at high frequencies. Consequently, the net magnetomotive force and flux in the core become negligible. As a result, the high-frequency impedance characteristics are remarkably similar for windings with and without a magnetic core. These findings are substantiated through rigorous simulations and empirical measurements. [ABSTRACT FROM AUTHOR]

In this paper we present a scalable approach based on the latency-based linear multistep compound method to use graphic processing unit (GPU) to accelerate the power system simulations with electromagnetic transients. To balance between the computational load and accuracy, we modeled the power system using shifted frequency analysis. Then, to efficiently exploit the hardware, our computational approach is designed to utilize both data-parallel and task-parallel execution. In addition, a graph-based thread safety design is introduced to achieve high scalability in the paralleled component computations. Furthermore, our implementation introduces a translation layer for different heterogeneous computing frameworks during compile time, so that a wide range of GPU devices can be supported without losing performance. Finally, benchmark results show that our approach achieves faster-than-real-time capability for systems with hundreds to thousands of nodes. [Display omitted] • Exploits data- and task-parallelism together in an automated way. • A graph-based approach to ensure thread safety to increase scalability. • A compile-time translation layer to allow execution on various platforms. • Faster-than-real-time for system with more than 10,000 dynamic components. • 82 × faster compared to an optimized sequential simulation. [ABSTRACT FROM AUTHOR]

Grid forming control applied to power converters termed as grid forming converters (GFC) interfacing storage and renewable generation has been identified as a potential solution to facilitate a more significant penetration of converter-based renewable generation in the power system. The emulated electromechanical model in the GFC is also the synchronization unit which typically utilizes measured output active power from the GFC as the feedback variable. However, this feature has opened up a concern on the transient stability due to loss of synchronism under significant transient events in the power systems, which include frequency change, phase jump, and voltage dips. This paper presents a quantitative and illustrative analysis of the impact of the current limit in GFC on the transient stability of a system comprising of GFC. Furthermore, a solution based on virtual active power is proposed to improve the transient stability margin of the GFC when the GFC enters the current limit. Finally, the analysis and the proposed method to enhance the transient stability are verified by Power hardware in the loop (PHIL) experimental tests. • Outlined the challenges for grid forming converters when current limit is present. • Provided clarification to the transient stability for grid forming converters. • Provided a quantitative analysis of transient stability for grid forming converters. • Introduced virtual power in control design to extend the transient stability margin. • Conducted Power-HiL evaluation on a modified low inertia IEEE 9-bus system. [ABSTRACT FROM AUTHOR]

• Efficient dynamic modelling framework for the analysis of fair-sized DC microgrids. • Nodal formulation combined with Newton–Raphson and implicit trapezoidal methods. • BESS, CHP units, PV plants and series connected DC/DC converters can be studied. • Results are validated versus EMT simulation conducted in Simscape Electrical. • Small errors are obtained with a small fraction of time taken by the EMT simulation. This paper introduces a novel modelling framework for conducting dynamic analysis of DC microgrids (MG), considering components such as battery energy storage systems (BESS), combined heat and power (CHP) cogeneration, photovoltaic (PV) plants and DC/DC converters. The MG dynamics are accurately captured using well-founded modelling practices of the power system transient analysis field. Firstly, the power device models are derived based on fundamental operating principles using a lumped-type parameter modelling approach. Secondly, the DC microgrid is formulated using nodal power injections, which is combined with Newton–Raphson and implicit trapezoidal methods to efficiently solve fair-sized networks of arbitrary topology. The dynamic outcomes of a 13-bus MG were compared with those of an electromagnetic transient (EMT) simulation conducted in Simscape Electrical for load and solar irradiance changes and for a DC/DC converter outage. For these events, errors smaller than 2.5% were yielded by the new approach, only requiring 3.1% of the computing time employed by the EMT simulation. The method's applicability was also showcased by assessing the dynamic performance of a larger DC microgrid containing 118 buses, twelve distributed generators and five BESS, which was subjected to typical contingencies such as load increases and distribution line disconnections. [ABSTRACT FROM AUTHOR]

• Truely on-site measurements of the transient voltage in a 220 kV substation; • Statistical analysis on the difference between on-site measured transient voltage waveforms and standard impulse waveforms; The electromagnetic transient overvoltage in the substation is an important factor that affects the life of insulation equipment. For evaluate the economy and reliability of the insulation design of substation equipment, it is necessary to study and analyze the actual measured overvoltage waveforms in the substation. In this paper, firstly, the 3018 pieces of overvoltage data monitored in the 220 kV substation from 2018 to 2019 are preprocessed to obtain the required overvoltage waveform. Next, by analyzing and classifying the overvoltage data, four typical overvoltage waveforms suffered by the insulation equipment in the substation are extracted. Combined with the IEC60060 standard, the time parameters of the overvoltage waveform are selected and defined: wave-front time (T f), half-value time (T half), main oscillation frequency (f), and attenuation constant (α). Further, statistical analysis is performed on the parameters of each waveform. The distribution law, distribution characteristics and distribution range of the parameters are obtained. Finally, the parameters of four typical overvoltage waveforms are summarized and compared, the cumulative distribution functions are obtained. This results can guide and optimize the insulation design of the insulation equipment in the substation, reduce design errors. It provide data support for the economy and reliability of insulation design. [ABSTRACT FROM AUTHOR]

• The virtual inertia hidden in the energy storage device is explored to obtain the synchronous operation capability. • A novel virtual shaft is added to the VSG to capture more transient energy from synchronous generators to energy storage devices. • The virtual shaft control strategy of the hybrid energy storage device is proposed for both frequency support and oscillation suppression. • The proposed control strategy is tested on a controller hardware-in-the-loop platform. If the hybrid energy storage device (HESD) with virtual inertia is coupled with synchronous generators (SGs) by a virtual shaft, the stronger transient stability of the power system can be achieved if more transient energy is captured by renewable power generation. In this paper, the conversion relationships between the static energy of the HESD and the kinetic energy of the SG are established. The virtual inertia hidden in the HESD is then explored to obtain the synchronous operation capability. To capture more transient energy from SGs to HESD, a novel virtual shaft is added to the VSG, and moreover, the impacts of HESD coupled with the virtual shaft on system transient stability are analyzed. Using the Hamiltonian energy function, the necessary conditions for improving the transient energy capture efficiency of the HESD are presented, and thus the virtual shaft control strategy of the HESD is proposed to integrate the power support functions for system frequency regulation and power oscillation damping. Finally, a typical test system with high penetration of photovoltaic arrays and HESDs is implemented on a hardware-in-the-loop platform. The results demonstrate that under the proposed control strategy, the transient stability of system frequency and rotor angle can be both significantly improved. [ABSTRACT FROM AUTHOR]

This paper proposes a methodology for modeling and simulating electromagnetic transients in power transmission cables with arbitrary cross-sections, usually applied in offshore power transmission and variable speed machine drive. This way, a sector-shaped cable is modeled taken into account its frequency-dependent parameters. Both impedance and admittance parameters are calculated by using the Finite Element Method, without analytic formulations based on the approach by an equivalent cylindrical cross-section, which leads to several inaccuracies. In sequence, the cable is decoupled into its four propagation modes by using an approximate modal transformation matrix with real and constant terms. Finally, each mode is modeled directly in the time domain by equivalent electric circuits, in which the lumped circuit elements are obtained from the rational function approach and fitting techniques. • Electrical parameters of submarine cables based on geometric characteristics and finite elements method. • Frequency-dependent equivalent circuit in the time domain by using the Vector Fitting algorithm. • Determining the modal transformation matrix with more than three propagation modes. • Modeling and simulation methodology applied to cables with arbitrary cross section and multiple modes. [ABSTRACT FROM AUTHOR]

• Supervisory control of CIRs improves transient stability of synchronous generators. • CIRs are allowed to participate in dynamic grid support during abnormal conditions. • Control of CIRs can be performed during fault and post-fault periods. • The increasing penetration of CIRs can help improve the transient stability margins. Power-electronic converters are increasingly utilized to integrate renewable and distributed energy resources (DERs) with conventional power grids. The increasing penetration of converter-interfaced resources (CIRs) could, in turn, influence the transient stability of traditional synchronous generators (SGs) in power systems due to their fast response and low inertia nature. This paper evaluates the transient stability of power systems containing SGs and grid-following CIRs under various control schemes and penetration of CIRs. The critical clearing time (CCT) of the SGs is used as the criterion for assessing transient stability following a fault. It is demonstrated that stability margins can be improved by actively controlling the grid-following CIRs during fault and post-fault periods. The proposed method is shown to increase the CCT compared to the conventional/alternative approaches, particularly the common practice that requires CIRs to inject only reactive power to support/regulate voltage during the fault period. It is also shown that with increased penetration of CIRs, if controlled appropriately, the transient stability of SGs can be improved, which is not commonly expected in low-inertia systems. [ABSTRACT FROM AUTHOR]

The high penetration of photovoltaic (PV) in power grids typically leads to the displacement of traditional synchronous generators (SGs). However, with a high penetration of PV, fewer SGs are running, and the sharing of responsibility to control the system frequency is reduced and easily exacerbates the problem of reduced inertia response in the power system. This can increase frequency deviation when there is a load-generation imbalance or unexpected disturbances. The limited amount of inertial response from the PV generation means that it cannot provide the same frequency support as SGs. Therefore, this paper suggests a fast frequency control (FFC) technique for the battery energy storage system (BESS) to reduce the instantaneous frequency deviation (IFD) in the Ethiopian grid. The authors specifically provide knowledge of the modeling of droop-type controlled BESS, which can provide additional damping, enhance the inertial ability of the system, and reduce IFD. The simulation results indicate the effectiveness of BESS in mitigating the adverse inertial impact of PV and meeting the necessary grid requirement. The proposed method was tested on the Ethiopian power system model through simulations by using DIgSILENT simulation software. To validate the model, transient frequency simulation studies are performed for various fault conditions, and comparisons are made with and without BESS for different levels of PV penetration. • A model of the Ethiopia–Kenya LCC HVDC interconnection is developed. • The study examines the integration of large and small-scale grid-connected PV systems into the power grid at varying penetration levels. • Frequency responses are analyzed for PV penetration levels (15%–45%) with load or generation contingency. • BESS modeled and controlled using droop control with PI-lead and lead–lag algorithms, considering frequency deviation input. [ABSTRACT FROM AUTHOR]

• This paper establishes a small signal model of variable speed pumped storage unit with full size converter. • The oscillation modes and key influencing factors are clarified. • A coordinated control strategy for suppressing the ultra-low frequency oscillation is proposed. The research on control strategies of the variable speed pumped storage unit with full size converter (FSC-VSPSU), mainly focuses on the rapidity of power regulation. But the speed oscillation and slow speed regulation performance caused by fast power regulation are ignored, which is not conducive to the safe and efficient operation of the unit. This article investigates the dynamic stability characteristics of the FSC-VSPSU in detail. In turn, the stability risks are clarified and serve for the design of its control strategy and the improvement of operational efficiency. The small-signal model of FSC-VSPSU considering the variation of water head and load in fast power mode is established. The dominant instability control link and key parameters are revealed based on the eigenvalue analysis. Oscillation mode analysis shows that the unit has a wide-band oscillation characteristic. The dominant oscillation mode is the ultra-low frequency oscillation (ULFO) caused by the governor control system. To suppress the ULFO and improve the optimal speed tracking performance of the unit to the greatest extent, a coordinated control strategy of governor variable parameter control and governor power system stabilizer (GPSS) is proposed. The electromagnetic transient simulation based on PSCAD verifies the effectiveness of the proposed measures. [ABSTRACT FROM AUTHOR]

• An electromagnetic transient model of the Sen Transformer (ST) with inter-turn fault (ITF) is proposed. • The hysteresis effects are considered as it affect the accuracy of the analytical results of the proposed model. • The current variation of the ST in the event of an ITF is analyzed. • The effects of number of fault turns and fault locations on the current of the ST with ITF are presented. In order to analyze the electromagnetic characteristics of the Sen Transformer (ST) in the event of an inter-turn fault (ITF), an electromagnetic transient model of the ST with ITF based on reluctance is proposed in this paper. Firstly, the magnetic equivalent circuit model of the ST with ITF is established based on the magnetic coupling relationship among the internal windings of the ST with ITF. Secondly, the electrical analytical model for the current in each winding of the ST with ITF is derived from the electrical connection established the ST with ITF and the external system. Finally, the electromagnetic transient model of the ST with ITF can be obtained by combining the magnetic equivalent circuit model with the electrical analytical model. The J-A hysteresis model is employed for representing the saturation characteristics of the iron core and the hysteresis effects. Meanwhile, an energy method is used to calculate the leakage reluctance between the windings. Three case studies have been conducted with the assistance of MATLAB and ANSYS/Maxwell. The results of the analytical calculations are compared with the time-domain simulation to verify the validity of the model. Furthermore, the growth of the current in the fault phase is significant after an ITF occurs in the ST, while the growths of the currents in the non-fault phases are very small. Moreover, the effects of the number of fault turns and the fault location on the current in the ST with ITF are further analyzed. [ABSTRACT FROM AUTHOR]

• The vulnerable branches which affect the transient voltage security are identified. • Image-form samples combine grid structure and power flow information visually. • Knowledge visualization makes CNN-based transient voltage stability assessment model more understandable and reliable. • A comprehensive vulnerability indicator integrates the knowledge in CNN, grid topology and branch state. • The proposed method is demonstrated on a real-life provincial grid with renewable energy integration. Because of the increasing proportion of grid-connected converters, the transient voltage problem has increased the risk of the secure and stable operation of power systems. As the extension of transient voltage stability assessment (TVSA), transient voltage vulnerability assessment is the key technique to detect the crucial elements which can cause the insecurity risk of power system transient voltage. Although deep learning-based TVSA models have demonstrated the high accuracy, it is more important to display the knowledge learnt by the models and utilize it to recognize the weakness of transient voltage. This paper presents a transient voltage vulnerability assessment method by knowledge visualization of convolutional neural network (CNN). First, the image-form sample construction method is proposed to characterize the power system operating condition, which prepares for training CNN-based TVSA model. Then, the knowledge in TVSA model is visualized based on Gradient-weighted Class Activation Mapping (Grad-CAM) and Activation Maximization (AM) algorithms, which is analyzed from the perspective of power system stability. Finally, a comprehensive vulnerability indicator is proposed for identify the weakness of transient voltage, which combines the knowledge inside the TVSA model and the indicators with clear physical meaning. Simulation results of the New England 39-bus test system and the real Shandong provincial power grid in China demonstrate that the visualization makes the model more reliable and the proposed method can accurately identify the vulnerable branches. [ABSTRACT FROM AUTHOR]

The deployment of sophisticated and costly large-capacity wind turbines continues to rise. It is urgent for precise real-time simulation to accurately identify and address potential problems. However, the existing solutions, which joint various simulation platforms, suffer from the disadvantages of complex architecture and high cost. This paper proposes a CPU-FPGA heterogeneous computing-based real-time simulation platform for detailed wind turbine model (DWTM). DWTM encompasses the turbine model (covering the inflow wind, aerodynamic, and mechanical dynamic), the electrical model (covering the electromagnetic transient), and the control system. The real-time operating system is introduced to guarantee the real-time performance of the turbine model and control system in the CPU. FPGA is used to perform real-time electrical model calculation. Furthermore, a general FPGA solver for electromagnetic transients is designed. It can accommodate various circuit topologies without the need for recompiling the FPGA code. Finally, the real-time simulation performance and accuracy are verified. The coupled dynamics between the turbine and electrical models are investigated under multiple power grid and wind conditions. • The CPU-FPGA heterogeneous computing platform for the real-time simulation of detailed wind turbine model is developed. • A general FPGA solver is designed and developed for various circuit topologies. • The coupling phenomena between power grid faults and mechanical component vibrations are analyzed comprehensively under multiple power grid conditions and wind conditions. [ABSTRACT FROM AUTHOR]

• An end-to-end fault situation identification framework for distribution networks. • A high-precision digital twin agent with parallel and ultra-real-time computing and identifying. • Skip-connected dilated convolutional networks and knowledge sharing via multi-task learning. • An automated hyper-parameter tuning strategy. • Case studies validate the effectiveness and robustness of the approach. The gradual integration of distributed wind power into distribution networks presents significant challenges for identifying faults, as it requires accurate and timely fault identification based on large-scale data. This paper proposes a novel fault situation identification framework driven by digital twins to overcome the existing bottleneck of asynchronous online fault identification and offline post-event analysis. The framework employs a high-precision digital twin avatar with parallel strategies of fully electromagnetic transient calculation to obtain the real-time operation status of distribution networks connected with distributed wind power. Furthermore, the framework employs skip-connected dilated causal convolution to mine meaningful multi-time-scale features from massive data, while using an automatic hyper-parameter tuning strategy. A case study based on IEEE 33-node standard distribution network and a real-world distribution network demonstrates the effectiveness of this framework, achieving ultra-real-time and high-precision simulation and effective fault identification even under noise or missing data, accelerating traditional post-fault analysis to microsecond-level situation identification. [ABSTRACT FROM AUTHOR]

The uneven distribution of renewable energy supply and demand promotes the development of high-voltage direct current transmission. As the critical reactive power compensation equipment for high voltage direct current transmission, the synchronous condenser must have a strong overload capability. One of the critical factors limiting the improvement of its overload capacity is the reliability of the end winding, which depends on the magnitude of the force on end windings during dynamic large reactive power output. Therefore, this paper proposes a coupling model of transient electromagnetic force for the high voltage direct current transmission system and the end zone of the synchronous condenser. The transient response of the synchronous condenser under different fault degrees is calculated, analyzed, and verified by experiments. Based on the current response of the synchronous condenser, the transient electromagnetic force on end windings is calculated. The distribution law of the force on end windings of the synchronous condenser under different degrees of dynamic reactive power compensation process is revealed. Further, the regions on end windings with larger force during strong overload are indicated. The optimizing fixation scheme for end windings is proposed according to the distribution features of the force, which can improve the operational reliability of end windings. • Force on end windings under dynamic large reactive power output is important. • Propose transient force coupling model of end winding under large reactive power. • Reveal the law of the force on end winding during dynamic reactive power process. • Indicate the regions with a larger force under large reactive power. • Propose an optimized fixing scheme to enhance the reliability of the end windings. [ABSTRACT FROM AUTHOR]

The resilience of power systems is critical in mitigating faults caused by the impending effects of climate change. Typical operational methods, such as network reconfiguration, may be insufficient to mitigate faults in the event of a contingency. On the other hand, reducing system demand may help increase the number of restored loads. As a result, this paper proposes a novel self-healing optimization approach based on a power grid concept known as conservative voltage reduction (CVR), which results in system demand reduction. The proposed optimization model is formulated as a mixed integer non-linear (MINLP) problem to fulfill an objective of minimizing unserved loads within the system. Voltage, thermal capacity, system radiality, and several more constraints have been taken into consideration while formulating the proposed model to handle both grid-connected and isolated modes of operation. Both dispatchable and non-dispatchable distributed generators (DGs) are taken into consideration. Dispatchable DGs are assumed to be capable of switching back and forth between constant power (PQ) and droop controls for the purpose of grid following and grid forming in grid-connected and isolated modes of operation, respectively. The proposed optimization approach is coded and solved using the General Algebraic Modeling System (GAMS) software. The IEEE 69-bus power distribution test system is utilized to test the validity and superiority of the proposed model. The results show that the proposed model effectively increases the system resilience by reducing the unserved power/energy within the system following a contingency. • Optimized MINLP fuses Reconfiguration with Conservative Voltage Reduction (CVR). • Increased system resilience against climactic faults using the proposed fusion. • Proposed approach was tested on grid connected &isolated systems following a fault. • Deterministic and probabilistic analysis was explored alongside proposed approach. • The proposed fusion recovered up to 6% more load than reconfiguration without CVR. [ABSTRACT FROM AUTHOR]

• An analytical criterion to investigate the transient angle stability of the grid-forming controlled type-4 wind turbine during the fault is proposed. • Various key factors on the transient stability of the system are jointly and comprehensively revealed by using the criterion. • Impacts of the reactive power control and time-delay of power references switching on the transient stability are studied by utilizing phase portrait of the derived third-order large-signal model. Thanks to the ability of the inertia provision and the voltage support, the virtual synchronous generator with reactive power control (RPC) is a promising solution among various grid-forming control schemes. This paper analyzes the transient angle stability of the grid-connected type-4 wind turbine with virtual synchronous generator and reactive power control strategy during the fault. By deriving the analytical criterion with the transient energy function, various key factors on the transient stability of the system can be revealed comprehensively and jointly. Additionally, the impacts of the integral coefficient of the RPC and the power reference switching delay on the transient stability are also analyzed by plotting the phase portraits of the derived third-order large-signal model of the grid-connected wind turbine system. The analytical result can be helpful for the determination of the parameters of the grid-connected wind turbine in order to keep transient stable and keep connected with the grid during the fault. Finally, the robustness and the effectiveness of the theoretical analysis results are validated by the electromagnetic transient simulation in MATLAB/Simulink under various conditions. [ABSTRACT FROM AUTHOR]

• The state-of-the-art research advances in power system restoration with large renewable penetration are reviewed from different system levels, i.e., transmission system, distribution system, and coordinated transmission and distribution system. • The methods of handling renewable power uncertainty during system restoration are summarized. • The laboratory validations and practical applications of the renewable power system restoration strategies are reviewed. • Promising research directions for renewable system restoration are provided, including uncertainty handling, artificial intelligence techniques, transient stability issues, cyber-physical interlinking, and multi-energy coupling. The catastrophic blackout events and ever-increasing penetration of renewable power generation highlight an advanced restoration strategy to effectively and reliably employ renewable power generation to contribute to renewable power system restoration. This paper reviews the research advances of power system restoration involving large renewable penetration, and the methods of handling renewable power uncertainty during restoration are also summarized. First, the transmission system restoration processes are divided into three sequential stages: a) black-start, b) network reconfiguration and c) load restoration, and the research advances of these three restoration stages involving large renewable generation are presented. Then, the distribution system restoration assisted by multiple flexible resources, such as renewable distributed generators, remotely-controlled switches, energy storage systems, and soft open points, are reviewed with emerging techniques, including micro-grids, multi-agent systems, repair crews, and mobile power sources. Furthermore, with the growing activeness and flexibility of the distribution system, the coordinated transmission and distribution system restoration and their information interactions are also discussed. Finally, for practical applications, the laboratory validations of restoration strategies using realistic power grid data, real-world restoration strategies, decision support systems, and field tests of black-start procedures are introduced to complete this literature review. Effectively deploying renewable power sources can significantly improve the power system restoration efficiency, and their inherent uncertainty should be carefully handled. Moreover, promising research trends are provided to improve the power system restoration with large renewable penetration. [ABSTRACT FROM AUTHOR]